#!/bin/bash
set -eo pipefail

help=$(cat <<EOF
Generate Tarball with Bios image and MANIFEST Script

Generates a Bios image tarball from given file as input.
Creates a MANIFEST for image verification and recreation
Packages the image and MANIFEST together in a tarball

usage: gen-bios-tar [OPTION] <Bios FILE>...

Options:
   -o, --out <file>       Specify destination file. Defaults to
                          $(pwd)/obmc-bios.tar.gz if unspecified.
   -s, --sign <path>      Sign the image. The optional path argument specifies
                          the private key file. Defaults to the bash variable
                          PRIVATE_KEY_PATH if available, or else uses the
                          open-source private key in this script.
   -m, --machine <name>   Optionally specify the target machine name of this
                          image.
   -v, --version <name>   Specify the version of bios image file
   -h, --help             Display this help text and exit.
EOF
)

#################################################################
# It's the OpenBMC "public" private key (currently under
# meta-phosphor/recipes-phosphor/flash/files/OpenBMC.priv):
# https://gerrit.openbmc-project.xyz/c/openbmc/openbmc/+/8949/15/
# meta-phosphor/common/recipes-phosphor/flash/files/OpenBMC.priv
#
#################################################################
private_key=$'-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----
'

do_sign=false
PRIVATE_KEY_PATH=${PRIVATE_KEY_PATH:-}
private_key_path="${PRIVATE_KEY_PATH}"
outfile=""
machine=""
version=""

while [[ $# -gt 0 ]]; do
  key="$1"
  case $key in
    -o|--out)
      outfile="$2"
      shift 2
      ;;
    -s|--sign)
      do_sign=true
      if [[ -n "${2}"  && "${2}" != -* ]]; then
        private_key_path="$2"
        shift 2
      else
        shift 1
      fi
      ;;
    -m|--machine)
      machine="$2"
      shift 2
      ;;
    -v|--version)
      version="$2"
      shift 2
      ;;
    -h|--help)
      echo "$help"
      exit
      ;;
    -*)
      echo "Unrecognised option $1"
      echo "$help"
      exit
      ;;
    *)
      file="$1"
      shift 1
      ;;
  esac
done

if [ ! -f "${file}" ]; then
  echo "${file} not found, Please enter a valid Bios image file"
  echo "$help"
  exit 1
fi

if [[ -z $version ]]; then
  echo "Please provide version of image with -v option"
  exit 1
fi

if [[ -z $outfile ]]; then
  outfile=$(pwd)/obmc-bios.tar.gz
else
  if [[ $outfile != /* ]]; then
    outfile=$(pwd)/$outfile
  fi
fi

scratch_dir=$(mktemp -d)
# Remove the temp directory on exit.
# The files in the temp directory may contain read-only files, so add
# --interactive=never to skip the prompt.
trap '{ rm -r --interactive=never ${scratch_dir}; }' EXIT

if [[ "${do_sign}" == true ]]; then
  if [[ -z "${private_key_path}" ]]; then
    private_key_path=${scratch_dir}/OpenBMC.priv
    echo "${private_key}" > "${private_key_path}"
    echo "Image is NOT secure!! Signing with the open private key!"
  else
    if [[ ! -f "${private_key_path}" ]]; then
      echo "Couldn't find private key ${private_key_path}."
      exit 1
    fi

    echo "Signing with ${private_key_path}."
  fi

  public_key_file=publickey
  public_key_path=${scratch_dir}/$public_key_file
  openssl pkey -in "${private_key_path}" -pubout -out "${public_key_path}"
fi

manifest_location="MANIFEST"
files_to_sign="$manifest_location $public_key_file"

# Go to scratch_dir
cp "${file}" "${scratch_dir}"
cd "${scratch_dir}"
files_to_sign+=" $(basename "${file}")"

echo "Creating MANIFEST for the image"
echo -e "purpose=xyz.openbmc_project.Software.Version.VersionPurpose.Host\n\
version=$version" > $manifest_location

if [[ -n "${machine}" ]]; then
    echo -e "MachineName=${machine}" >> $manifest_location
fi

if [[ "${do_sign}" == true ]]; then
  private_key_name=$(basename "${private_key_path}")
  key_type="${private_key_name%.*}"
  echo KeyType="${key_type}" >> $manifest_location
  echo HashType="RSA-SHA256" >> $manifest_location

  for file in $files_to_sign; do
    openssl dgst -sha256 -sign "${private_key_path}" -out "${file}.sig" "$file"
  done

  additional_files="*.sig"
fi

# shellcheck disable=SC2086
# Do not quote the files variables since they list multiple files
# and tar would assume to be a single file name within quotes
tar -czvf $outfile $files_to_sign $additional_files
echo "Bios image tarball is at $outfile"
